The present invention relates to artificial teeth, and more particularly to posterior teeth having a novel non-interlocking shape that minimizes harmful side stresses and lateral shifting of dentures.
Most previously known artificial teeth are essentially imitations of natural teeth insofar as their configuration is concerned, taking advantage of the efficient biting and chewing surfaces of interlocking cusps that are the product of evolution. There are, however, certain well known problems associated with these immitative or anatomical artificial teeth, largely attributable to the fact that they are not firmly anchored in the mouth, as in the case of natural teeth. The lower denture in particular is not held as securely as desired because the tongue divides the area between the left and right gum ridges that would otherwise provide a suction surface. Movement or wobble of the dentures causes soreness, food packing, physiological deterioration of gum tissue and increased looseness, these problems being very serious in many cases.
One proposed artifical tooth construction, described in my U.S. Pat. No. 3,060,576, utilizes teeth that are shaped to provide stabilizing forces directed toward the lingual side of the lower teeth. Like other previously known arrangements, it employs interlocking cusps after the manner of natural teeth, the stabilizing forces being produced by the inclined orientation of mutually engaging surfaces.
It has been found that substantial undesired lateral shifting of the dentures is attributable to side stresses. When interlocking cusp teeth are used, these stresses may be caused, even when not chewing, by sideways movement of the lower jaw and transformation of vertical forces into horizontal forces by inclined tooth surfaces.
A primary objective of the invention is to provide artificial posterior teeth that minimize undesirable side stresses, thereby reducing or eliminating undesired denture shifting and physiological problems, such as impaired temporo-mandibular joint function.